CN117133208A

CN117133208A - Driving backboard, detection method thereof and display panel

Info

Publication number: CN117133208A
Application number: CN202210554231.1A
Authority: CN
Inventors: 万宝红; 汪浩; 李洋; 廖小刚; 李云泽
Original assignee: Chengdu Vistar Optoelectronics Co Ltd
Current assignee: Chengdu Vistar Optoelectronics Co Ltd
Priority date: 2022-05-20
Filing date: 2022-05-20
Publication date: 2023-11-28

Abstract

The embodiment of the invention discloses a driving backboard, a detection method thereof and a display panel. Wherein, the drive backplate includes: the device comprises a first welding electrode, a second welding electrode and a plurality of cascaded shift registers. The shift register has an output terminal for outputting a scan signal. The first welding electrode and the second welding electrode are used for being connected with the light-emitting unit, the first welding electrode is connected with the output end of the last-stage shift register in the detection stage, the second welding electrode is connected with the power line, so that the light-emitting unit is driven to emit light through a scanning signal output by the last-stage shift register in the detection stage and a signal on the power line, and the working state of the shift register is judged through the light-emitting state of the light-emitting unit. The technical scheme of the embodiment of the invention not only realizes the detection of the working state of the shift register, but also is beneficial to reducing the test difficulty and the test cost and reducing the material waste.

Description

Driving backboard, detection method thereof and display panel

Technical Field

The embodiment of the invention relates to the technical field of display, in particular to a driving backboard, a detection method thereof and a display panel.

Background

With the continuous development of display technology, performance requirements of display panels are increasing. The display panel comprises shift registers for scanning and driving the sub-pixel units, and because the number of the sub-pixel units is very large, if the working state of the shift registers is abnormal, the display of the screen body is abnormal. Therefore, it is necessary to test the performance of the shift register before the display panel is put into use. However, the existing test method for the shift register has the problems of high test difficulty, high test cost, serious material waste and the like.

Disclosure of Invention

The embodiment of the invention provides a driving backboard, a detection method thereof and a display panel, which are used for realizing the detection of the working state of a shift register, reducing the testing difficulty and the testing cost and reducing the material waste.

In a first aspect, an embodiment of the present invention provides a driving backplate, including:

a plurality of cascaded shift registers, the shift registers having output terminals for outputting scan signals;

the first welding electrode is connected with the output end of the shift register at the last stage in the detection stage, and the second welding electrode is connected with a power line so as to drive the light-emitting unit to emit light through a scanning signal output by the shift register at the last stage and a signal on the power line in the detection stage, and the working state of the shift register is judged through the light-emitting state of the light-emitting unit.

Optionally, the driving back plate further includes a pixel circuit, a first power signal line for providing a first power voltage to the pixel circuit, a second power signal line for providing a second power voltage to the pixel circuit, and an initialization signal line for providing an initialization voltage to the pixel circuit to initialize the pixel circuit;

The power supply line includes any one of the first power supply signal line, the second power supply signal line, and the initialization signal line.

Optionally, the driving backboard is provided with a display area, and the first welding electrode and the second welding electrode are positioned in the display area;

preferably, the driving backboard comprises a pixel circuit, the first welding electrode is connected with the output end of the pixel circuit, and the first welding electrode is further used for disconnecting the output end of the shift register of the last stage after the detection stage is completed, so that the light emitting unit is driven to display through signals output by the pixel circuit and signals on the power line in the display stage.

Optionally, the driving back plate has a display area and a non-display area, and the first welding electrode and the second welding electrode are located in the non-display area.

Optionally, the light emitting unit includes a first electrode and a second electrode;

the first welding electrode is used for being connected with the first electrode, the second welding electrode is used for being connected with the second electrode, and the power line comprises a second power signal line; or,

the first welding electrode is used for being connected with the second electrode, the second welding electrode is used for being connected with the first electrode, and the power line comprises a first power signal line.

Optionally, a plurality of cascaded shift registers and at least one pair of the first welding electrode and the second welding electrode, which are arranged corresponding to the cascaded shift registers, are respectively arranged on two sides of the driving backboard;

the first welding electrode positioned on one side of the driving backboard is connected with the output end of the shift register at the last stage of the side in the detection stage, so that the scanning signal output by the shift register at the last stage of the side and the signal on the power line drive the light-emitting unit to emit light in the detection stage, and the working state of the shift register at the side is judged according to the light-emitting state of the light-emitting unit;

the first welding electrode positioned on the other side of the driving backboard is connected with the output end of the shift register at the last stage of the side in the detection stage, so that the scanning signal output by the shift register at the last stage of the side and the signal on the power line drive the light-emitting unit to emit light in the detection stage, and the working state of the shift register at the side is judged according to the light-emitting state of the light-emitting unit.

In a second aspect, an embodiment of the present invention further provides a method for detecting a driving backboard, where the driving backboard includes: a plurality of cascaded shift registers, the shift registers having output terminals for outputting scan signals; the first welding electrode is connected with the output end of the shift register of the last stage in the detection stage, and the second welding electrode is connected with a power line; the detection method of the driving backboard comprises the following steps:

In the detection stage, connecting the light emitting unit to the first welding electrode and the second welding electrode;

controlling a plurality of cascaded shift registers to output scanning signals step by step, so as to drive the light emitting units to emit light through the scanning signals output by the shift registers of the last stage and the signals on the power line;

and judging the working state of the shift register according to the light-emitting state of the light-emitting unit.

Optionally, the light emitting state of the light emitting unit includes a light emitting duration and a light emitting brightness;

when the light emitting unit is driven to emit light by a turn-off level signal in a scanning signal output by the shift register of the last stage and a signal on the power line, judging the working state of the shift register according to the light emitting state of the light emitting unit, including:

if the luminous duration of the luminous unit in one scanning period is equal to the duration of the turn-off level signal, and the ratio of the luminous brightness of the luminous unit to the maximum brightness is more than 0.5 and less than 1, determining that the working state of the shift register is normal, otherwise, determining that the working state of the shift register is abnormal; the maximum brightness is corresponding to the brightness when the light-emitting unit emits light according to the turn-off level signal and the signal on the power line in one scanning period; when the light emitting unit is driven to emit light by a conduction level signal in a scanning signal output by the shift register at the last stage and a signal on the power line, judging the working state of the shift register according to the light emitting state of the light emitting unit, wherein the method comprises the following steps:

If the luminous duration of the luminous unit in one scanning period is equal to the duration of the conducting level signal, and the ratio of the luminous brightness of the luminous unit to the maximum brightness is more than 0 and less than 0.5, determining that the working state of the shift register is normal, otherwise determining that the working state of the shift register is abnormal;

the maximum brightness is corresponding to the brightness when the light-emitting unit emits light according to the conducting level signal and the signal on the power line in one scanning period;

preferably, the method for detecting a driving backboard further comprises:

and controlling the duration of the conduction level signal in the scanning signal output by the shift register in the detection stage to be longer than the duration of the conduction level signal in the scanning signal output by the shift register in the display stage and shorter than one half of the duration of one scanning period.

Optionally, the driving backboard is provided with a display area and a non-display area;

the first welding electrode and the second welding electrode are positioned in the display area; the driving backboard comprises a pixel circuit, and the first welding electrode is connected with the output end of the pixel circuit; the driving backboard further comprises a third welding electrode and a fourth welding electrode which are positioned in the display area and used for being connected with the light-emitting unit, the third welding electrode is connected with the output end of the pixel circuit, and the fourth welding electrode is connected with a power line; the detection method of the driving backboard further comprises the following steps:

If the working state of the shift register is normal, reserving the light-emitting units connected with the first welding electrode and the second welding electrode, and connecting the light-emitting units on the third welding electrode and the fourth welding electrode to finish the setting of all the light-emitting units in the display area;

disconnecting the first welding electrode from the output end of the shift register of the last stage;

alternatively, the first welding electrode and the second welding electrode are located in the non-display area; the detection method of the driving backboard further comprises the following steps:

if the working state of the shift register is normal, removing the light-emitting units connected with the first welding electrode and the second welding electrode, and setting the light-emitting units in the display area;

and disconnecting the first welding electrode from the output end of the shift register of the last stage.

In a third aspect, an embodiment of the present invention further provides a display panel, including the driving back plate according to the first aspect; the first welding electrode is disconnected with the output end of the shift register of the last stage.

The driving backboard, the detection method thereof and the display panel provided by the embodiment of the invention can be connected with the light-emitting unit through the first welding electrode and the second welding electrode in the detection stage so as to drive the light-emitting unit to emit light by utilizing the scanning signal output by the last stage of shift register and the signal on the power line, thereby judging the working state of the shift register through the light-emitting state of the light-emitting unit and realizing the detection of the working state of the shift register. Compared with the prior art, the working state of the shift register can be detected only by setting a small number of test light-emitting units, and the light-emitting state of the test light-emitting units can reflect the working state of the shift register, so that the test difficulty is reduced. According to the scheme, all the display light-emitting units are not required to be transferred to the display area of the driving backboard before the detection stage, and the transfer of all the display light-emitting units can be performed after the detection stage is completed, so that the waste of the display light-emitting units caused by the fact that the driving backboard is scrapped due to abnormal working state of the shift register can be avoided. Moreover, the working state of the shift register is detected without adopting the array test AT equipment, so that the purchase and transformation costs of the test equipment are reduced. In summary, the technical scheme of the embodiment of the invention not only realizes the detection of the working state of the shift register, but also is beneficial to reducing the test difficulty and the test cost and reducing the material waste.

It should be understood that the description in this section is not intended to identify key or critical features of the embodiments of the invention or to delineate the scope of the invention. Other features of the present invention will become apparent from the description that follows.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the description of the embodiments will be briefly described below, and it is apparent that the drawings in the following description are only some embodiments of the present invention, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic structural diagram of a driving back plate according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of a pixel circuit applied to a driving backplate;

FIG. 3 is a schematic diagram of another driving back plate according to an embodiment of the present invention;

FIG. 4 is a schematic diagram of a shift register applied to a driving back plate;

FIG. 5 is a schematic diagram showing a driving timing of a shift register;

FIG. 6 is a schematic diagram of another driving back plate according to an embodiment of the present invention;

Fig. 7 is a schematic flow chart of a detection method of a driving backboard according to an embodiment of the present invention;

fig. 8 is a schematic structural diagram of another driving back plate according to an embodiment of the present invention.

Detailed Description

In order that those skilled in the art will better understand the present invention, a technical solution in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in which it is apparent that the described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the present invention without making any inventive effort, shall fall within the scope of the present invention.

It should be noted that the terms "first," "second," and the like in the description and the claims of the present invention and the above figures are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged where appropriate such that the embodiments of the invention described herein may be implemented in sequences other than those illustrated or otherwise described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

As described in the background art, the existing test method for the shift register has the problems of high test difficulty, high test cost, serious material waste and the like. The inventors found that the above problems occur for the following reasons: taking a Micro-LED display panel as an example for explanation, in the process of the Micro-LED display panel, a huge amount of Micro-LEDs are usually transferred onto a driving backboard containing a pixel circuit and a shift register by adopting a huge amount transfer technology, so that the problems of high process difficulty, high Micro-LED cost and the like of the huge amount transfer technology exist. In the related art, the working state of the shift register is usually tested after a large amount of transfer is completed, if the working state of the shift register is abnormal, abnormal display of the screen body can be caused, and waste of manpower, materials and cost of the prior process is caused. In addition, the related art generally adopts Array Test (AT) equipment to manually Test the shift register, the AT equipment may need to be modified before being applied to the Test, but the purchase cost, modification and other costs of the AT equipment are higher, the Test cost of the shift register is improved, the controllability of the manual Test is poor, the display panel is easily scratched, and the Test difficulty is higher.

In view of the foregoing, embodiments of the present invention provide a driving back plate. Fig. 1 is a schematic structural diagram of a driving back plate according to an embodiment of the present invention. Referring to fig. 1, the driving back plate includes a first bonding electrode 10, a second bonding electrode 20, and a plurality of cascaded shift registers 30.

The shift register 30 has an output terminal O for outputting a scan signal. The first welding electrode 10 and the second welding electrode 20 are used for being connected with a light-emitting unit, the first welding electrode 10 is connected with the output end O of the last stage of shift register 30 in the detection stage, the second welding electrode 20 is connected with a power line L, and the light-emitting unit is driven to emit light through a scanning signal output by the last stage of shift register 30 and a signal on the power line L in the detection stage, so that the working state of the shift register 30 is judged through the light-emitting state of the light-emitting unit.

Specifically, the first welding electrode 10 and the second welding electrode 20 are located at one side of the driving back plate, and are disposed in pairs on the driving back plate, at least one welding electrode pair 100 may be disposed on the driving back plate, each welding electrode pair 100 includes one first welding electrode 10 and one second welding electrode 20, and fig. 1 shows a case that three welding electrode pairs 100 are included on the driving back plate. The light emitting unit to which the first welding electrode 10 and the second welding electrode 20 are connected may include a light emitting device, for example, a light emitting device such as a Micro-LED or a Mini-LED. The light emitting unit includes two electrodes, and a first welding electrode 10 of each welding electrode pair 100 may be connected to one electrode of the light emitting unit and a second welding electrode 20 may be connected to the other electrode of the light emitting unit so that the light emitting unit is connected to the corresponding welding electrode pair 100.

The driving back plate has a display area AA and a non-display area NAA. The display area AA includes a plurality of rows of pixel circuits (not shown in fig. 1), the non-display area NAA is provided with a plurality of cascaded shift registers 30, and an input end of the first stage shift register 30 is connected to a start signal SIN, so that a timing sequence of the start signal SIN is shifted by the first stage shift register 30, and a scan signal is obtained and output through an output end O. The output end O of the previous stage shift register 30 is connected to the input end of the next stage shift register 30, so that the scan signal output by the previous stage shift register 30 is used as the input signal of the next stage shift register 30, and thus each stage shift register 30 can output the scan signal with sequentially shifted time sequence step by step. The output end O of each stage of shift register 30 may be connected to at least one row of pixel circuits through a scan line at the same time, so as to output a scan signal to the corresponding pixel circuit row, so as to realize scan driving of each pixel circuit row, and make the pixel circuit drive the corresponding light emitting unit to emit light. For convenience of description, the light emitting unit to which the first welding electrode 10 and the second welding electrode 20 are connected is referred to as a test light emitting unit, and the light emitting unit driven by the pixel circuit is referred to as a display light emitting unit in each of the following embodiments to distinguish the two.

There are various structures of the pixel circuits in the driving back plate, and fig. 2 is a schematic diagram of a structure of a pixel circuit applied to the driving back plate. Taking fig. 2 as an example, the pixel circuit 40 includes a driving transistor DT, a first transistor T1, and a second transistor T2. The first transistor T1 may be turned on or off in response to the first Scan signal Scan1 to write the initialization voltage Vref to the gate of the driving transistor DT when turned on, thereby initializing the gate voltage of the driving transistor DT. The second transistor T2 may be turned on or off in response to the second Scan signal Scan2 to write the Data voltage Data to the gate electrode of the driving transistor DT when turned on, so that the driving transistor DT drives the display light emitting unit 50 to perform light emitting display at a responsive brightness according to the Data voltage Data in a light emitting stage. The Scan signal output from the shift register 30 may be the first Scan signal Scan1 or the second Scan signal Scan2. In the case where the pixel circuit further includes other switching transistors, the scanning signal output from the shift register 30 may be a scanning signal input from the gate of the other switching transistors.

In the detection phase, the test light emitting unit may be connected to the corresponding first and second welding electrodes 10 and 20. The plurality of cascaded shift registers 30 are controlled to output the scan signal step by step so as to transmit the scan signal to the first welding electrode 10 through the shift register 30 of the last stage, and to supply the signal to the power line L so as to transmit the signal to the second welding electrode 20 through the power line L, so that one electrode of the test light emitting unit is connected to the scan signal output by the shift register 30 of the last stage, and the other electrode is connected to the signal on the power line L. The scanning signal comprises an on-level signal and an off-level signal, the on-level signal is a signal for controlling the transistor to be on, the off-level signal is a signal for controlling the transistor to be off, one of the on-level signal and the off-level signal can be a low-level signal, and the other one can be a high-level signal. The signal on the power line L is a fixed level signal, which may be a low level signal or a high level signal. For example, the test light emitting unit may emit light according to a high level signal and a fixed level signal in the scan signal when the fixed level signal is a low level signal, and the test light emitting unit may emit light according to a low level signal and a fixed level signal in the scan signal when the fixed level signal is a high level signal.

When the working states of the shift registers 30 at all stages are normal, the duration of the on-level signal and the off-level signal in the scanning signal output by the shift register 30 at the last stage is a fixed value, so that the light emitting state of the test light emitting unit for emitting light according to the scanning signal output by the shift register 30 at the last stage and the signal on the power line L is fixed, for example, the light emitting duration of the test light emitting unit is a first duration, the light emitting brightness is a first brightness, and both the first duration and the first brightness are fixed values. When the operating state of at least one stage of shift registers 30 in each stage of shift registers 30 is abnormal, the scanning signal output by the last stage of shift register 30 is also abnormal, so that the duration of the on-level signal and the off-level signal in the scanning signal output by the last stage of shift register 30 is changed, and the light emitting state of the test light emitting unit for emitting light according to the scanning signal output by the last stage of shift register 30 and the signal on the power line L is changed, for example, the light emitting time of the test light emitting unit is longer than or shorter than the first duration, and the light emitting brightness is higher than or lower than the first brightness. Therefore, the operating state of the shift register 30 can be judged from the light emission state of the test light emitting unit.

Taking the example that the driving backboard is a Micro-LED driving backboard as an illustration, the test light-emitting unit and the display light-emitting unit can be Micro-LEDs. In the related art, generally, after the process of driving the back plate is completed, a huge amount of Micro-LEDs are transferred to the display area AA of the driving back plate, and then the working state of the shift register is tested. In this embodiment, the working state of the shift register 30 can be determined by testing the light emitting state of the light emitting unit, so that a small number of test light emitting units can be connected to the first welding electrode 10 and the second welding electrode 20 before the Micro-LED is transferred to the driving back plate, and the working state of the shift register 30 can be tested by the test light emitting unit. After the test is completed, the Micro-LEDs are transferred to the drive back plate in large quantities.

According to the technical scheme, the light-emitting unit can be connected through the first welding electrode and the second welding electrode in the detection stage, so that the scanning signal output by the last stage of shift register and the signal on the power line are utilized to drive the light-emitting unit to emit light, the working state of the shift register is judged through the light-emitting state of the light-emitting unit, and the working state detection of the shift register is realized. Compared with the prior art, the working state of the shift register can be detected only by setting a small number of test light-emitting units, and the light-emitting state of the test light-emitting units can reflect the working state of the shift register, so that the test difficulty is reduced. According to the scheme, all the display light-emitting units are not required to be transferred to the display area of the driving backboard before the detection stage, and the transfer of all the display light-emitting units can be performed after the detection stage is completed, so that the waste of the display light-emitting units caused by the fact that the driving backboard is scrapped due to abnormal working state of the shift register can be avoided. Moreover, the working state of the shift register is detected without adopting the array test AT equipment, so that the purchase and transformation costs of the test equipment are reduced. In summary, the technical scheme of the embodiment of the invention not only realizes the detection of the working state of the shift register, but also is beneficial to reducing the test difficulty and the test cost and reducing the material waste.

Referring to fig. 1 and 2, the driving back plate further includes a first power signal line L1, a second power signal line L2, and an initialization signal line L3. The first power signal line L1 is for supplying a first power voltage VDD to the pixel circuit 40, the second power signal line L2 is for supplying a second power voltage VSS to the pixel circuit 40, and the initialization signal line L3 is for supplying an initialization voltage Vref to the pixel circuit 40 to initialize the pixel circuit 40. In the present embodiment, the power supply line L to which the second welding electrode 20 is connected may be any one of the first power supply signal line L1, the second power supply signal line L2, and the initialization signal line L3.

Specifically, the first power voltage VDD is positive, the second power voltage VSS is negative or 0V, and in the light emitting stage, the first electrode of the driving transistor DT is connected to the first power voltage VDD, the second end of the display light emitting unit 50 is connected to the second power voltage VSS, a discharge path is formed between the first power signal line L1 and the second power signal line L2, and the driving transistor DT generates a driving current to drive the display light emitting unit 50 to emit light. The initialization voltage Vref has a low voltage value and can be used to initialize the gate of the driving transistor DT. In other embodiments, the initialization voltage Vref on the initialization signal line L3 may also be a voltage for initializing the first terminal of the display light emitting unit 50.

When the first power signal line L1 is used as the power line L, the test light emitting unit may emit light according to the low level signal and the first power voltage VDD in the scan signal output from the last stage of shift register 30 in the detection stage, so as to realize the detection of the working state of the shift register 30. When the second power signal line L2 is used as the power line L, the test light emitting unit may emit light according to the high level signal in the scan signal output from the last stage of shift register 30 and the second power voltage VSS in the detection stage, so as to implement detection of the working state of the shift register 30. When the initialization signal line L3 is used as the power line L, the test light emitting unit may emit light according to the high level signal and the initialization voltage Vref in the scan signal output from the last stage of shift register 30 in the detection stage, so as to realize the detection of the working state of the shift register 30. Therefore, any one of the first power signal line L1, the second power signal line L2, and the initialization signal line L3 may be used as the power line L. In other embodiments, if the driving back plate further includes a signal line for transmitting other fixed voltages, the signal line may also be used as the power line L to drive the test light emitting unit to emit light through the fixed voltage on the signal line and the low level signal or the high level signal in the scanning signal output by the last stage of shift register 30, so as to realize the detection of the working state of the shift register 30.

Fig. 3 is a schematic structural diagram of another driving back plate according to an embodiment of the present invention. Referring to fig. 3, alternatively, a plurality of cascaded shift registers 30 are disposed on both sides of the driving back plate, and at least one pair of first and second welding electrodes 10 and 20 (i.e., at least one welding electrode pair 100) are disposed corresponding to the plurality of cascaded shift registers 30. The first welding electrode 10 positioned at one side of the driving back plate is connected with the output end O of the shift register 30 at the last stage of the side in the detection stage, so that the light-emitting unit is driven to emit light through the scanning signal output by the shift register 30 at the last stage of the side and the signal on the power line L in the detection stage, and the working state of the shift register 30 is judged through the light-emitting state of the light-emitting unit. The first welding electrode 10 on the other side of the driving back plate is connected with the output end O of the shift register 30 of the last stage of the side in the detection stage, so that the light-emitting unit is driven to emit light through the scanning signal output by the shift register 30 of the last stage of the side and the signal on the power line L in the detection stage, and the working state of the shift register 30 of the side is judged through the light-emitting state of the light-emitting unit.

Fig. 3 shows a case where both the left and right sides of the driving back plate include a plurality of cascaded shift registers 30, and three pairs of welding electrodes 100 are provided corresponding to the shift registers 30 of each side. For example, the three welding electrode pairs 100 at each side may be respectively used to connect light emitting units of different colors, such as a red light emitting unit, a green light emitting unit, and a blue light emitting unit. The first welding electrode 10 of the three welding electrode pairs 100 on the left side of the driving back plate is connected to the output end O of the shift register 30 of the last stage on the left side in the detection stage, so that the operating state of the shift register 30 of each stage on the left side is detected by the test light emitting unit connected to the welding electrode pairs 100 on the left side of the driving back plate. The first welding electrode 10 of the three welding electrode pairs 100 on the right side of the driving back plate is connected to the output end O of the shift register 30 of the last stage on the right side in the detection stage, so that the working state of the shift register 30 of each stage on the right side is detected by the test light emitting unit connected to the welding electrode pairs 100 on the right side of the driving back plate.

Referring to fig. 2 and 3, the first welding electrode 10 and the second welding electrode 20 may be disposed in either the display area AA or the non-display area NAA. Optionally, when the first welding electrode 10 and the second welding electrode 20 are located in the display area AA, the first welding electrode 10 is connected to the output terminal N of the pixel circuit 40, and the first welding electrode 10 is further configured to disconnect from the output terminal O of the last stage shift register 30 after the detection stage is completed, so as to drive the light emitting unit to display through the signal output by the pixel circuit 40 and the signal on the power line L in the display stage.

The test light emitting unit 60 includes a first electrode d1 and a second electrode d2, the first welding electrode 10 is used for connecting the first electrode d1, the second welding electrode 20 is used for connecting the second electrode d2, and the power line L includes a second power signal line L2. The test light emitting unit 60 includes a light emitting device D1, an anode of the light emitting device D1 may serve as a first electrode D1, and a cathode of the light emitting device D1 may serve as a second electrode D2. The output terminal N of the pixel circuit 40 may be one end of the pixel circuit 40 outputting a driving current to the light emitting unit, for example, one end of the pixel circuit 40 connected to the anode of the light emitting device.

Illustratively, in the detection stage, the first electrode d1 of the test light emitting unit 60 is connected to the first welding electrode 10, the second electrode d2 of the test light emitting unit 60 is connected to the second welding electrode 20, the first welding electrode 10 is connected to the output end O of the last stage shift register 30, and at this time, the test light emitting unit 60 emits light according to the high level signal in the scan signal output by the last stage shift register 30 and the second power voltage VSS on the second power signal line L2, so as to realize the detection of the operating state of the shift register 30. In the detection stage, in the case where the pixel circuit 40 does not drive the test light emitting unit 60 to emit light, for example, a light emission control transistor (not shown in fig. 2) is further disposed on the discharge path between the first power signal line L1 and the second power signal line L2, the light emission control transistor is controlled to be turned off in the detection stage, or no signal is provided to the first power signal line L1, so that the discharge path between the first power signal line L1 and the second power signal line L2 cannot be turned on in the detection stage, and the pixel circuit 40 cannot drive the test light emitting unit 60 to emit light, thereby avoiding affecting the detection of the operating state of the shift register 30.

After the detection stage is completed, the connection between the first welding electrode 10 and the output terminal O of the last stage shift register 30 may be disconnected, so that the first welding electrode 10 is connected to the output terminal N of the pixel circuit 40, so that the first electrode d1 of the test light emitting unit 60 is connected to the output terminal N of the pixel circuit 40 through the first welding electrode 10, and the second electrode d2 of the test light emitting unit 60 is connected to the second power signal line L2 through the second welding electrode 20 to be connected to the second power voltage VSS. Thus, in the display stage, the driving transistor DT in the pixel circuit 40 may supply the driving current to the test light emitting unit 60 when the first to second power signal lines L1 to L2 form the discharge path, and the test light emitting unit 60 may display as the display light emitting unit 50.

The above embodiment has been described taking a case where the first welding electrode 10 and the second welding electrode 20 are located in the display area AA, the first welding electrode 10 is connected to the output terminal N of the pixel circuit 40, the first welding electrode 10 is connected to the first electrode d1 of the test light emitting unit 60, the second welding electrode 20 is connected to the second electrode d2 of the test light emitting unit 60, and the power line L includes the second power signal line L2 as an example. In other embodiments, when the first welding electrode 10 and the second welding electrode 20 are located in the display area AA, the first welding electrode 10 may be further configured to connect to the second electrode of the test light emitting unit, the second welding electrode 20 is connected to the first electrode of the test light emitting unit, and the power line L includes a first power signal line L1, so that the test light emitting unit emits light according to a low level signal in the scan signal output by the last stage shift register 30 and the first power voltage VDD on the first power signal line L1 in the detection stage, to implement detection of the operating state of the shift register 30.

Optionally, the light emitting state of the test light emitting unit includes a light emitting duration and a light emitting luminance. When the test light emitting unit is driven to emit light by the turn-off level signal in the scan signal output by the last stage shift register 30 and the signal on the power line L, if the light emitting duration of the test light emitting unit in one scan period is equal to the duration of the turn-off level signal, and the ratio of the light emitting brightness of the test light emitting unit to the maximum brightness is greater than 0.5 and less than 1, the working state of the shift register is determined to be normal, otherwise, the working state of the shift register is determined to be abnormal. One scanning period may be one frame, and the maximum brightness is the brightness corresponding to the test light emitting unit when the test light emitting unit emits light according to the off level signal and the signal on the power line L in one scanning period.

Fig. 4 is a schematic circuit diagram of a shift register applied to a driving back plate. Fig. 5 is a schematic diagram of a driving timing of a shift register. The drive timing in fig. 5 can be used to drive the shift register in fig. 4 to operate during the detection phase. Referring to fig. 3 to 5, the shift register may include a third transistor T3, a fourth transistor T4, a fifth transistor T5, a sixth transistor T6, a seventh transistor T7, an eighth transistor T8, a ninth transistor T9, a tenth transistor T10, a first capacitor C1, and a second capacitor C2. The third transistor T3 is connected to the start signal SIN (i.e., the start signal SIN or the Scan signal outputted from the shift register of fig. 3), the ninth transistor T9 is connected to the high level signal VGH, the tenth transistor T10 is connected to the low level signal VGL, the sixth transistor T6 and the seventh transistor T7 are connected to the first clock signal CLK1, the fourth transistor T4 and the eighth transistor T8 are connected to the second clock signal CLK2, and the output terminal O outputs the Scan signal Scan.

In the following description, referring to fig. 3 to 5, the on-level signal in the Scan signal Scan is a low-level signal, the off-level signal is a high-level signal, the second power signal line L2 is used as the power line L, that is, the signal on the power line L is a low-level signal, the refresh frequency of driving the back plate is 60Hz, the duration t of one Scan period is approximately 16600 μs, the duration t2=41.5 μs of the low-level signal in the Scan signal Scan output by the shift register 30 in the detection stage, and the total duration t1+t3= 16558.85 μs of the high-level signal are taken as examples.

Table 1 shows the correspondence relationship of the operating state of the shift register in this case with the light emission luminance and the light emission duration of the test light emitting unit. The light emitting luminance ratio Lv of the test light emitting unit represents a ratio of light emitting luminance of the test light emitting unit in one scan period to maximum luminance, which may be luminance of the test light emitting unit that emits light according to the high level signal and the second power supply voltage VSS in one scan period. The light emitting duration of the test light emitting unit is the light emitting duration of one scan period.

TABLE 1

As shown in table 1, the multiple outputs, the output clock signal, no output, the output constant high and the output constant low are all abnormal operation states of the shift register 30. When the shift register 30 is in a normal working state, the test light emitting unit drives the test light emitting unit to emit light according to a high level signal in the Scan signal Scan output by the shift register 30 of the last stage and the second power supply voltage VSS. The light-emitting brightness of the test light-emitting unit is related to the light-emitting time, and the longer the light-emitting time is, the higher the light-emitting brightness is when the current for driving the test light-emitting unit to emit light is fixed. When the shift register 30 is in the normal operation state, the light emitting duration of the test light emitting unit in one scan period is t1+t3= 16558.85 μs, and the ratio (t1+t3)/t of the light emitting duration to the total duration of one scan period is greater than 50% and less than 100%, so that the light emitting luminance of the test light emitting unit in one scan period is greater than 50% and less than the highest luminance and is close to the highest luminance, that is, the light emitting luminance ratio Lv of the test light emitting unit is greater than 50% and less than 100% and is close to 100%. When the shift registers 30 are in the multi-output state, it indicates that there is a short circuit between the output terminals O of the shift registers 30 of adjacent stages, the Scan signal Scan output by one shift register 30 includes a plurality of low-level signals, the light-emitting brightness of the corresponding test light-emitting unit is lower than the light-emitting brightness of the normal state, and the light-emitting time is shorter than the light-emitting time of the normal state. When the shift register 30 is in the state of outputting the clock signal, the second clock signal CLK2 accessed by the eighth transistor T8 may be directly output through the output terminal O, where the light emitting brightness of the corresponding test light emitting unit is half of the maximum brightness, and the light emitting time is half of the duration of one scan period. When the shift register 30 is in the no-output state, the light emission luminance and the light emission time of the corresponding test light emitting unit are both 0. When the shift register 30 is in the state of outputting a constant high, the high level signal VGH accessed by the ninth transistor T9 may be directly output through the output terminal O, where the light emitting luminance of the corresponding test light emitting unit is the maximum luminance, and the duration of the light emitting time equal to one scan period is equal to T. When the shift register 30 is in the output constant low state, the seventh transistor T7 may form a path with the output terminal O, and the low level signal VGL is directly output through the output terminal O, so that the test light emitting unit does not emit light, and both the light emitting luminance and the light emitting time thereof are 0. Therefore, the scheme realizes the judgment of different working states of the shift register 30 according to the light emitting time and the light emitting brightness of the test light emitting unit.

The above embodiment will be described taking, as an example, only a case where the off-level signal in the Scan signal Scan outputted from the last stage shift register 30 is a high-level signal and the signal on the power supply line L is a low-level signal. In other embodiments, if the off-level signal in the Scan signal Scan output by the last stage shift register 30 is a low-level signal and the signal on the power line L is a high-level signal, the test light emitting unit may still emit light according to the off-level signal in the Scan signal Scan output by the last stage shift register 30 and the signal on the power line L, and in this case, the specific principle of determining the working state of the shift register 30 may be understood with reference to the above embodiments, which is not repeated herein.

Optionally, the duration of the on-level signal in the Scan signal Scan output by the shift register in the detection stage is controlled to be greater than the duration of the on-level signal in the Scan signal Scan output by the shift register in the display stage and less than one half of the duration of one Scan period. For example, referring to fig. 5, when a scanning period time t=16600 μs, a time t 2=3 μs of a conducting level signal in a Scan signal Scan output by the shift register in the display stage may be set, and a time t 2=41.5 μs of a conducting level signal in a Scan signal Scan output by the detection stage, so that it is convenient to measure a light emitting time and a light emitting brightness of the test light emitting unit, so that differences between light emitting time and light emitting brightness corresponding to different operation states of the shift register are easier to measure, thereby improving accuracy of operation state judgment of the shift register.

Fig. 6 is a schematic structural diagram of another driving back plate according to an embodiment of the present invention. Referring to fig. 2 and 6, alternatively, when the first welding electrode 10 and the second welding electrode 20 are disposed in the non-display area NAA, the first welding electrode 10 is used to connect the second electrode of the test light emitting unit, the second welding electrode 20 is used to connect the first electrode of the test light emitting unit, the test light emitting unit includes a light emitting device, an anode of the light emitting device may be used as the first electrode of the test light emitting unit, a cathode of the light emitting device may be used as the second electrode of the test light emitting unit, and the power line L includes a first power signal line L1.

Illustratively, when the first welding electrode 10 and the second welding electrode 20 are disposed in the non-display area NAA, the test light emitting unit is only used to detect the operation state of the shift register 30, and is not used as the display light emitting unit. In the detection stage, the test light emitting unit 60 emits light according to the first power voltage VDD on the first power signal line L1 and the low level signal in the scan signal outputted from the last stage shift register 30 to realize the operation state detection of the shift register 30.

The above embodiment has been described taking a case where the first welding electrode 10 and the second welding electrode 20 are located in the non-display area NAA, the first welding electrode 10 is connected to the second electrode of the test light emitting unit, the second welding electrode 20 is connected to the first electrode of the test light emitting unit, and the power line L includes the first power signal line L1 as an example. In other embodiments, when the first welding electrode 10 and the second welding electrode 20 are located in the non-display area NAA, the first welding electrode 10 may be further configured to be connected to a first electrode of the test light emitting unit, the second welding electrode 20 is connected to a second electrode of the test light emitting unit, and the power line L includes any one of the second power signal line L2 and the initialization signal line L3, so that the test light emitting unit emits light according to a high level signal in the scan signal output by the last stage shift register 30 and the second power voltage VSS on the second power signal line L2 in the detection stage, or emits light according to a high level signal in the scan signal output by the last stage shift register 30 and the initialization voltage Vref on the initialization signal line L3, thereby realizing the detection of the operating state of the shift register 30.

Optionally, the light emitting state of the test light emitting unit includes a light emitting duration and a light emitting luminance. When the test light emitting unit is driven to emit light by the on-level signal in the scan signal output by the last stage shift register 30 and the signal on the power line L, if the light emitting duration of the test light emitting unit in one scan period is equal to the duration of the on-level signal, and the ratio of the light emitting brightness of the test light emitting unit to the maximum brightness is greater than 0 and less than 0.5, the working state of the shift register 30 is determined to be normal, otherwise, the working state of the shift register 30 is determined to be abnormal. The maximum brightness is the brightness corresponding to the test light-emitting unit when the test light-emitting unit emits light according to the conducting level signal and the signal on the power line L in one scanning period.

In the following description, referring to fig. 4 to 6, the on-level signal in the Scan signal Scan is a low-level signal, the off-level signal is a high-level signal, the first power signal line L1 is used as the power line L, that is, the signal on the power line L is a high-level signal, the refresh frequency of driving the back plate is 60Hz, the duration t of one Scan period is approximately 16600 μs, the duration t2=41.5 μs of the low-level signal in the Scan signal Scan output by the shift register 30 in the detection stage is exemplified by the duration t1+t3= 16558.85 μs of the high-level signal.

Table 2 shows the correspondence relationship of the operating state of the shift register in this case with the light emission luminance and the light emission duration of the test light emitting unit. The light emitting luminance ratio Lv of the test light emitting unit represents a ratio of light emitting luminance of the test light emitting unit in one scan period to maximum luminance, which may be luminance of the test light emitting unit emitting light according to the first power supply voltage VDD and the low level signal in one scan period. The light emitting duration of the test light emitting unit is the light emitting duration of one scan period.

TABLE 2

As shown in table 2, the multiple outputs, the output clock signal, no output, the output constant high and the output constant low are all abnormal operation states of the shift register 30. When the shift register 30 is in a normal operation state and is normal, the test light emitting unit emits light according to the first power supply voltage VDD and a low level signal of the scan signal outputted from the last stage shift register 30. When the shift register 30 is in a normal working state, the light emitting duration of the test light emitting unit in one scanning period is t2=41.5 μs, and the ratio t2/t of the light emitting duration to the total duration of one scanning period is greater than 0 and less than 50%, so that the light emitting brightness of the test light emitting unit in one scanning period is greater than 0 and less than 50% of the highest brightness, that is, the light emitting brightness ratio Lv of the test light emitting unit is greater than 0 and less than 50%, the light emitting brightness of the test light emitting unit is weak, and the test light emitting unit emits light for a plurality of times in a plurality of scanning periods in a short time, so that the visual effect of flicker is presented. When the shift registers 30 are in the multi-output state, the Scan signal Scan output by one shift register 30 includes a plurality of low-level signals, and the test light emitting unit can be turned on for a plurality of times when the low-level signals appear in the Scan signal Scan, so that the light emitting brightness of the test light emitting unit is greater than the positive integer multiple of the light emitting brightness in the normal state, and the light emitting time is greater than the positive integer multiple of t 2. When the shift register 30 is in a state of outputting a clock signal, the light emitting luminance of the corresponding test light emitting unit is half of the maximum luminance, and the light emitting time is half of the duration of one scan period. When the shift register 30 is in the no-output state, the light emission luminance and the light emission time of the corresponding test light emitting unit are both 0. When the shift register 30 is in a state of outputting a constant high, the test light emitting unit does not emit light, and both the light emitting luminance and the light emitting time thereof are 0. When the shift register 30 is in a state of outputting constant low, the light emission luminance of the corresponding test light emitting unit is maximum luminance, and the light emission time is equal to the duration t of one scanning period. Therefore, the scheme realizes the judgment of different working states of the shift register 30 according to the light emitting time and the light emitting brightness of the test light emitting unit.

The above embodiment will be described taking, as an example, only a case where the on-level signal in the Scan signal Scan outputted from the last stage shift register 30 is a low-level signal and the signal on the power supply line L is a high-level signal. In other embodiments, if the on-level signal in the Scan signal Scan output by the last stage shift register 30 is a high-level signal and the signal on the power line L is a low-level signal, the test light emitting unit may still emit light according to the on-level signal in the Scan signal Scan output by the last stage shift register 30 and the signal on the power line L, and in this case, the specific principle of determining the working state of the shift register 30 may be understood with reference to the above embodiments, which is not repeated herein.

The embodiment of the invention also provides a display panel which comprises the driving backboard in each embodiment of the invention. The display panel may be a Micro-LED display panel or a Mini-LED display panel, etc. The first welding electrode in the display panel is disconnected with the output end of the last stage of shift register, so that the scanning signal output by the last stage of shift register is prevented from being transmitted to the first welding electrode to influence the operation of the display panel. The display panel provided by the embodiment of the invention comprises the driving backboard in each embodiment of the invention, so that the display panel has the corresponding functional structure and beneficial effects of the driving backboard, and the description is omitted here.

The embodiment of the invention also provides a detection method of the drive backboard, which is suitable for the drive backboard in each embodiment. Fig. 7 is a schematic flow chart of a detection method of a driving backboard according to an embodiment of the invention. Referring to fig. 7, the method for detecting the driving back plate specifically includes the following steps:

s110, connecting the light emitting unit to the first welding electrode and the second welding electrode in the detection stage.

S120, controlling a plurality of cascaded shift registers to output scanning signals step by step, so as to drive the light emitting units to emit light through the scanning signals output by the shift registers of the last stage and signals on the power line.

S130, judging the working state of the shift register according to the light-emitting state of the light-emitting unit.

On the basis of the above-described embodiment, optionally, the light emission state of the light emitting unit includes a light emission period and a light emission luminance; when the light emitting unit is driven to emit light by the off level signal in the scan signal outputted from the last stage shift register and the signal on the power line, step S130 specifically includes:

if the light emitting duration of the light emitting unit in one scanning period is equal to the duration of the turn-off level signal and the ratio of the light emitting brightness of the light emitting unit to the maximum brightness is greater than 0.5 and less than 1, determining that the working state of the shift register is normal, otherwise determining that the working state of the shift register is abnormal.

The maximum brightness is the brightness corresponding to the light-emitting unit when the light-emitting unit emits light according to the turn-off level signal and the signal on the power line in one scanning period.

Alternatively, when the light emitting unit is driven to emit light by the on level signal in the scan signal outputted from the last stage shift register and the signal on the power line, step S130 specifically includes:

if the light emitting duration of the light emitting unit in one scanning period is equal to the duration of the on level signal, and the ratio of the light emitting brightness of the light emitting unit to the maximum brightness is greater than 0 and less than 0.5, determining that the working state of the shift register is normal, otherwise, determining that the working state of the shift register is abnormal.

The maximum brightness is the brightness corresponding to the light-emitting unit when the light-emitting unit emits light according to the conducting level signal and the signal on the power line in one scanning period;

optionally, the method for detecting the driving backboard further includes: the duration of the conduction level signal in the scanning signal output by the control shift register in the detection stage is longer than that of the conduction level signal in the scanning signal output by the control shift register in the display stage and shorter than one half of that of one scanning period.

Fig. 8 is a schematic structural diagram of another driving back plate according to an embodiment of the present invention. Referring to fig. 8, alternatively, the first welding electrode 10 and the second welding electrode 20 are positioned in the display area AA, the first welding electrode 10 is connected to the output terminal N of the pixel circuit, the second welding electrode 20 is connected to the second power signal line L2, the driving back plate further includes a third welding electrode 70 and a fourth welding electrode 80 positioned in the display area AA for connecting two electrodes of the display light emitting unit 50, the third welding electrode 70 is connected to the output terminal N of the pixel circuit 40, and the fourth welding electrode 80 is connected to the second power line VSS. Correspondingly, the detection method of the driving backboard further comprises the following steps:

if the working state of the shift register is normal, reserving the light-emitting units connected with the first welding electrode and the second welding electrode, and connecting the light-emitting units on the third welding electrode and the fourth welding electrode to finish the setting of all the light-emitting units in the display area; and disconnecting the first welding electrode from the output end of the shift register of the last stage.

Referring to fig. 2, 3 and 8, in this embodiment, in an exemplary manner, in the detection stage, the test light emitting unit 60 may be connected to the first welding electrode 10 and the second welding electrode 20 in the first display area AA1 and the second display area AA2, the working state of the shift register 30 is determined by the test light emitting unit 60, if the working state of the shift register 30 is normal, the test light emitting unit 60 in the first display area AA1 and the second display area AA2 may be reserved, and the connection between the first welding electrode 10 and the output end O of the last stage shift register 30 may be disconnected, so that the test light emitting unit 60 is used as the display light emitting unit 50, and then the remaining display light emitting units 50 are connected to the welding electrodes in other areas of the display area AA, so as to complete the transfer of the remaining display light emitting units. The remaining display lighting units 50 may be transferred to the corresponding third and fourth welding electrodes 70 and 80 to complete the transfer of the respective display lighting units 50 in the display area AA. Compared with the prior art, the scheme does not need to remove the test light-emitting unit 60 after the detection stage is completed, which is beneficial to reducing the waste of the test light-emitting unit 60, and the scheme transfers the rest display light-emitting units 50 to the driving back plate with normal working state of the shift register 30 after the detection stage is completed, which is beneficial to avoiding the waste of the display light-emitting units 50 under the condition that the driving back plate is scrapped due to abnormal working state of the shift register 30.

The embodiment of the invention also provides another detection method of the driving backboard, which is suitable for the driving backboard in fig. 1, 3 and 8. The method specifically comprises the following steps:

step one, providing a driving backboard.

And secondly, connecting a test light-emitting unit on a first welding electrode and a second welding electrode in a display area of the driving backboard, so that one electrode of the test light-emitting unit is connected with the output end of the last stage of shift register through the first welding electrode, and the other electrode is connected with a power line through the second welding electrode.

And thirdly, supplying power to a power line through a module Test device (CT), and controlling a plurality of cascaded shift registers to output scanning signals step by step so as to drive a Test light-emitting unit to emit light through the scanning signals output by the shift registers of the last stage and signals on the power line.

And step four, judging the working state of the shift register according to the light-emitting state of the test light-emitting unit.

If the working state of the shift register is abnormal, executing the fifth step; if the working state of the shift register is normal, executing the step six.

And fifthly, scrapping the driving backboard.

And step six, transferring the rest display light-emitting units to a display area of the driving backboard.

For example, referring to fig. 8, after the operation state detection of the shift register 30 is completed by the test light emitting unit, the test light emitting unit may be left as the display light emitting unit, and then the remaining display light emitting units 50 are transferred onto the corresponding third and fourth welding electrodes 70 and 80 in the display area AA to complete the transfer of the respective display light emitting units in the display area AA. When the display light-emitting unit is a Micro-LED, the Micro-LED is transferred to a corresponding welding electrode in the display area AA in a huge amount, and then the bonding or the pressing is carried out, so that the connection between the Micro-LED and the corresponding welding electrode is realized.

And step seven, disconnecting the first welding electrode from the output end of the shift register of the last stage.

And step eight, performing lighting test through the module test equipment.

According to the technical scheme, the test light-emitting unit does not need to be removed after the detection of the shift register is completed, so that the waste of the test light-emitting unit is reduced, and the residual display light-emitting unit is transferred to the driving backboard with normal working state of the shift register after the detection stage is completed, so that the waste of the display light-emitting unit is avoided under the condition that the driving backboard is scrapped due to abnormal working state of the shift register.

Optionally, when the first welding electrode and the second welding electrode are located in the non-display area, the detection method of the driving back plate further includes:

if the working state of the shift register is normal, removing the light-emitting units connected with the first welding electrode and the second welding electrode, and setting the light-emitting units in the display area; and disconnecting the first welding electrode from the output end of the shift register of the last stage.

For example, referring to fig. 6, when the first welding electrode 10 and the second welding electrode 20 are disposed in the non-display area NAA, the test light emitting unit is used only to detect the operation state of the shift register 30, and not as the display light emitting unit. Therefore, after the detection stage is completed, if the working state of the shift register 30 is normal, the test light emitting units connected to the first welding electrode 10 and the second welding electrode 20 can be removed, the connection between the first welding electrode 10 and the output end O of the last stage shift register 30 is disconnected, and all the display light emitting units are connected to the display area AA, so as to complete the transfer of the display light emitting units.

The embodiment of the invention also provides another detection method of the drive backboard, which is suitable for the drive backboard in fig. 6. The method specifically comprises the following steps:

Step one, providing a driving backboard.

And thirdly, supplying power to the power line through the module testing equipment, and controlling the plurality of cascaded shift registers to output scanning signals step by step so as to drive the test light-emitting unit to emit light through the scanning signals output by the shift registers of the last stage and the signals on the power line.

And fifthly, scrapping the driving backboard.

And step six, transferring the display light-emitting unit to a display area of the driving backboard.

When the display light-emitting unit is a Micro-LED, the Micro-LED is transferred to a corresponding welding electrode in the display area AA in a huge amount, and then the bonding or the pressing is carried out, so that the connection between the Micro-LED and the corresponding welding electrode is realized.

And step seven, disconnecting the first welding electrode from the output end of the last stage of shift register, and removing the test light-emitting unit connected with the first welding electrode and the second welding electrode.

The first welding electrode and the output end of the last stage shift register can be disconnected in a laser cutting mode, and the test light-emitting unit connected on the first welding electrode and the second welding electrode is removed.

And step eight, performing lighting test through the module test equipment.

According to the technical scheme, after the detection of the shift register is completed, the connection between the first welding electrode and the output end of the last stage shift register is disconnected, and the test light-emitting units connected to the first welding electrode and the second welding electrode are removed, so that the influence on the normal operation of the driving backboard in the display stage is avoided.

The above embodiments do not limit the scope of the present invention. It will be apparent to those skilled in the art that various modifications, combinations, sub-combinations and alternatives are possible, depending on design requirements and other factors. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of the present invention.

Claims

1. A drive back plate, comprising:

2. The driving back panel according to claim 1, further comprising a pixel circuit, a first power supply signal line for supplying a first power supply voltage to the pixel circuit, a second power supply signal line for supplying a second power supply voltage to the pixel circuit, and an initialization signal line for supplying an initialization voltage to the pixel circuit to initialize the pixel circuit;

3. The drive backplate of claim 1, wherein the drive backplate has a display region in which the first and second welding electrodes are located;

4. The drive backplate of claim 1, wherein the drive backplate has a display region and a non-display region, the first and second welding electrodes being located in the non-display region.

5. The driving back plate according to claim 3 or 4, wherein the light emitting unit includes a first electrode and a second electrode;

6. The driving back plate according to claim 1, wherein a plurality of cascaded shift registers and at least one pair of the first welding electrode and the second welding electrode, which are provided corresponding to the plurality of cascaded shift registers, are provided on both sides of the driving back plate, respectively;

7. A method for detecting a driving back plate, the driving back plate comprising: a plurality of cascaded shift registers, the shift registers having output terminals for outputting scan signals; the first welding electrode is connected with the output end of the shift register of the last stage in the detection stage, and the second welding electrode is connected with a power line; the detection method of the driving backboard comprises the following steps:

8. The method for detecting a driving back plate according to claim 7, wherein the light emitting state of the light emitting unit includes a light emitting period and a light emitting luminance;

Preferably, the method for detecting a driving backboard further comprises:

9. The method of claim 7, wherein the drive back plate has a display area and a non-display area;

10. A display panel comprising the driving back plate according to any one of claims 1 to 6; the first welding electrode is disconnected with the output end of the shift register of the last stage.